1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_TIME64_H 3 #define _LINUX_TIME64_H 4 5 #include <linux/math64.h> 6 7 typedef __s64 time64_t; 8 typedef __u64 timeu64_t; 9 10 #include <uapi/linux/time.h> 11 12 struct timespec64 { 13 time64_t tv_sec; /* seconds */ 14 long tv_nsec; /* nanoseconds */ 15 }; 16 17 struct itimerspec64 { 18 struct timespec64 it_interval; 19 struct timespec64 it_value; 20 }; 21 22 /* Parameters used to convert the timespec values: */ 23 #define MSEC_PER_SEC 1000L 24 #define USEC_PER_MSEC 1000L 25 #define NSEC_PER_USEC 1000L 26 #define NSEC_PER_MSEC 1000000L 27 #define USEC_PER_SEC 1000000L 28 #define NSEC_PER_SEC 1000000000L 29 #define FSEC_PER_SEC 1000000000000000LL 30 31 /* Located here for timespec[64]_valid_strict */ 32 #define TIME64_MAX ((s64)~((u64)1 << 63)) 33 #define KTIME_MAX ((s64)~((u64)1 << 63)) 34 #define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC) 35 36 /* 37 * Limits for settimeofday(): 38 * 39 * To prevent setting the time close to the wraparound point time setting 40 * is limited so a reasonable uptime can be accomodated. Uptime of 30 years 41 * should be really sufficient, which means the cutoff is 2232. At that 42 * point the cutoff is just a small part of the larger problem. 43 */ 44 #define TIME_UPTIME_SEC_MAX (30LL * 365 * 24 *3600) 45 #define TIME_SETTOD_SEC_MAX (KTIME_SEC_MAX - TIME_UPTIME_SEC_MAX) 46 47 static inline int timespec64_equal(const struct timespec64 *a, 48 const struct timespec64 *b) 49 { 50 return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec); 51 } 52 53 /* 54 * lhs < rhs: return <0 55 * lhs == rhs: return 0 56 * lhs > rhs: return >0 57 */ 58 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs) 59 { 60 if (lhs->tv_sec < rhs->tv_sec) 61 return -1; 62 if (lhs->tv_sec > rhs->tv_sec) 63 return 1; 64 return lhs->tv_nsec - rhs->tv_nsec; 65 } 66 67 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec); 68 69 static inline struct timespec64 timespec64_add(struct timespec64 lhs, 70 struct timespec64 rhs) 71 { 72 struct timespec64 ts_delta; 73 set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec, 74 lhs.tv_nsec + rhs.tv_nsec); 75 return ts_delta; 76 } 77 78 /* 79 * sub = lhs - rhs, in normalized form 80 */ 81 static inline struct timespec64 timespec64_sub(struct timespec64 lhs, 82 struct timespec64 rhs) 83 { 84 struct timespec64 ts_delta; 85 set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec, 86 lhs.tv_nsec - rhs.tv_nsec); 87 return ts_delta; 88 } 89 90 /* 91 * Returns true if the timespec64 is norm, false if denorm: 92 */ 93 static inline bool timespec64_valid(const struct timespec64 *ts) 94 { 95 /* Dates before 1970 are bogus */ 96 if (ts->tv_sec < 0) 97 return false; 98 /* Can't have more nanoseconds then a second */ 99 if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) 100 return false; 101 return true; 102 } 103 104 static inline bool timespec64_valid_strict(const struct timespec64 *ts) 105 { 106 if (!timespec64_valid(ts)) 107 return false; 108 /* Disallow values that could overflow ktime_t */ 109 if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX) 110 return false; 111 return true; 112 } 113 114 static inline bool timespec64_valid_settod(const struct timespec64 *ts) 115 { 116 if (!timespec64_valid(ts)) 117 return false; 118 /* Disallow values which cause overflow issues vs. CLOCK_REALTIME */ 119 if ((unsigned long long)ts->tv_sec >= TIME_SETTOD_SEC_MAX) 120 return false; 121 return true; 122 } 123 124 /** 125 * timespec64_to_ns - Convert timespec64 to nanoseconds 126 * @ts: pointer to the timespec64 variable to be converted 127 * 128 * Returns the scalar nanosecond representation of the timespec64 129 * parameter. 130 */ 131 static inline s64 timespec64_to_ns(const struct timespec64 *ts) 132 { 133 return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec; 134 } 135 136 /** 137 * ns_to_timespec64 - Convert nanoseconds to timespec64 138 * @nsec: the nanoseconds value to be converted 139 * 140 * Returns the timespec64 representation of the nsec parameter. 141 */ 142 extern struct timespec64 ns_to_timespec64(const s64 nsec); 143 144 /** 145 * timespec64_add_ns - Adds nanoseconds to a timespec64 146 * @a: pointer to timespec64 to be incremented 147 * @ns: unsigned nanoseconds value to be added 148 * 149 * This must always be inlined because its used from the x86-64 vdso, 150 * which cannot call other kernel functions. 151 */ 152 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns) 153 { 154 a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns); 155 a->tv_nsec = ns; 156 } 157 158 /* 159 * timespec64_add_safe assumes both values are positive and checks for 160 * overflow. It will return TIME64_MAX in case of overflow. 161 */ 162 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs, 163 const struct timespec64 rhs); 164 165 #endif /* _LINUX_TIME64_H */ 166